简介
拦截器是基于web框架的调用，因此可以使用Spring的依赖注入（DI）进行一些业务操作。在SpringMVC中就是依赖于SpringMVC框架。在实现上基于Java的反射机制，属于面向切面编程（AOP）的一种运用。
主要工作场景
拦截器可以获取IOC容器中的各个bean，而过滤器就不行，所以在拦截器里注入一个service，可以调用业务逻辑。
拦截器只能对controller请求进行拦截，对其他的一些比如直接访问静态资源的请求则没办法进行拦截处理。
实现
1. 定义自己拦截器
/**
* Created by liusj 2019/6/29
*/
@Log
public class MyInterceptor extends HandlerInterceptorAdapter {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
log.info("MyInterceptor == preHandler ");
long startTime = System.nanoTime();
request.setAttribute("startTime", startTime);
return super.preHandle(request, response, handler);
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
log.info("MyInterceptor == postHandle ");
super.postHandle(request, response, handler, modelAndView);
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
log.info("MyInterceptor == afterCompletion ");
Long startTime = (Long) request.getAttribute("startTime");
long endTime = System.nanoTime();
// 打印出接口请求时间
log.info("This method expired :" + (endTime - startTime) / 1000000 + " 毫秒");
super.afterCompletion(request, response, handler, ex);
}
}
2. 配置(添加到Spring中)
@Configuration
public class MyMvcConfigure extends WebMvcConfigurerAdapter {
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(new MyInterceptor()).addPathPatterns("/");// 添加拦截路径
super.addInterceptors(registry);
}
}
由于SpringBoot2中WebMvcConfigurerAdapter过时@Deprecated，这里通过实现WebMvcConfigurer来实现拦截器的配置。
/**
* Created by liusj 2019/6/29
*/
@Configuration
public class MyMvcConfigure2 implements WebMvcConfigurer {
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(new MyInterceptor()).addPathPatterns("/");// 添加拦截路径
}
}
测试
@SpringBootApplication
@RestController
@Log
public class Application {
@RequestMapping(value = "/")
public String home() {
log.info("接口请求");
return "Hello Interceptor World";
}
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
测试结果
image.png
代码地址：https://github.com/lbshold/springboot/blob/master/Spring-Boot-Interceptor.zip
参考文献：
https://www.cnblogs.com/junzi2099/p/8022058.html
https://yq.aliyun.com/articles/688309?spm=a2c4e.11155435.0.0.78a13da0ZMVALr
